Gun-control advocates frequently cite the claim that the Brady Law has kept 1.5 million of the “wrong people” from getting a firearm, but the number has come under attack from gun-industry supporters as a bogus figure.

We’ve spent several days trying to unravel this question, because it is complicated and the data are sometimes murky. There are certainly gaps in the information — and a surprising lack of prosecutorial follow-up, which has further muddied the picture.

Let’s examine what is happening here.

The Facts

The Brady law — named after Ronald Reagan’s press secretary James Brady, who was gravely wounded in an assassination attempt on the president — requires federally licensed firearms sellers to check whether a purchaser is prohibited from owning a gun because of a criminal history. Generally, this is done through the National Instant Criminal Background Check System (NICS) through either the FBI or state agencies.

All told, in 2010, the FBI and state agencies denied a firearm to nearly 153,000 people via the NICS system. To keep things simple, we will focus on the FBI, using a report on the 2010 data by Ronald J. Frandsen of the Regional Justice Information Service.

About 99 percent of people who apply to buy a firearm are quickly cleared. But about 1 to 2 percent are denied, mainly because the records show that he or she has a felony indictment or conviction. The data also show that about 5 percent successfully appeal their denials.

Applications: 6,037,394

FBI denials: 72,659 (1.2 percent)

Appeals 16,513 (22.7 percent)

Successful appeals 3,491 (4.77 percent of denials)

The main reason listed for a denial is a felony conviction or indictment. Here are some of the key reasons:

Felony: 34,459 (47.4 percent)

Fugitive: 13,862 (19.1 percent)

State law prohibition: 7,666 (10.6 percent)

Drug use/addiction: 6,971 (9.6 percent)

But here is where it gets complicated. After a review by an arm of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF), only a tiny percentage of the cases are actually referred to ATF field divisions for possible referral to prosecutors. Here are the data for 2010 concerning FBI denials.

FBI denials referred to ATF: 76,142

Referred to field: 4,732 (6.2 percent)

Not referred to field: 68,209 (89.6 percent)

Overturned: 3,163 (4.2 percent)

At first glance, these numbers seemed astonishing. In other words, another 4 percent of initial denials were found to be wrong — and nine out of 10 were not deemed worthy of further investigation.

Then, virtually all of these cases were declined by ATF field offices. Here are some of the key reasons, with essentially one-quarter being a case of mistaken denial — even after weeks of investigation.

No prosecutorial merit: 1,661

Federal/state guidelines not met: 1,092

Not a prohibited person: 480

Closed by supervisor: 457

No potential or unfounded: 396

In the end, 62 cases were referred for prosecution, but most were declined by prosecutors or dismissed by the court. Out of the original 73,000 denials, there emerge just 13 guilty pleas.

Now, let’s back up a moment. As far as we can determine, the very low rate of referrals does not mean that most of the denials were “false positives” or unwarranted. But it does mean that such cases are a low priority for government prosecutors.

“Cases are referred to ATF field divisions in accordance with guidelines established by the field offices and U.S. Attorneys who work within each division’s territory. The guidelines basically cover the types of cases that are considered to be high priority,” said Frandsen. “Because the strength of a particular case will be determined by further investigation, it is more accurate to say that a case is not referred to a field division because it is not considered to be a high priority within that division.”

The current guidelines are not public, and Frandsen said ATF has not provided him with updated guidelines since at least 2006. He noted that his reports have routinely noted that “cases involving restraining orders, domestic violence misdemeanors, non-immigrant aliens, violent felonies, warrants, and indictments are most often included in referral criteria,” and ATF has never asked for an edit of this sentence.

A Justice Department official says that many fugitive cases are handled at that moment by local authorities, who simply send police to the gun shop to pick up the violator, which is why few of those cases are referred. But the official acknowledged that many other cases are difficult to prosecute, because they are essentially about having to prove that someone knowingly lied on a form. The official said priority instead is placed on potentially violent criminals.

In 2000, the Government Accountability Office issued a report that examined the referral process. It said most referrals were based on criminal history records involving violent felonies, serious drug trafficking or domestic violence misdemeanors. The report cited a lack of clear guidelines from U.S. attorneys about cases they would accept, even after ATF agents had spent as long as six months preparing the case for referral.

We believe that the number of referrals and prosecutions is low because of the difficulty in obtaining convictions in NICS cases. These cases lack “jury appeal” for various reasons. The factors prohibiting someone from possessing a firearm may have been nonviolent or committed many years ago. The basis for the prohibition may have been noncriminal (e.g., a dishonorable discharge from the U.S. military). It is also difficult to prove that the prohibited person was aware of the prohibition and intentionally lied to the FFL [federally licensed dealer]. We were also told that in parts of the United States where hunting historically has been part of the regional culture, juries are reluctant to convict a person who attempted to purchase a hunting rifle.

Even so, the review found that the ATF still forwarded too many cases that lacked prosecutorial merit. It also found a significant number of denials (21 percent) to applicants who should not have been prohibited from purchasing a firearm.

“The special agents we spoke with generally commented that they do not consider the vast majority of NICS referral subjects a danger to the public because the prohibiting factors are often minor or based on incidents that occurred many years in the past,” the report added. The report cited, as examples of people prohibited from buying gun, someone who had stolen four hubcaps and a person convicted in 1941 of stealing a pig. Of the cases reviewed by the IG, 48 percent of the crimes had occurred more than five years earlier — and 13 percent at least 20 years previously.

This report is 10 years old, but, if anything, the trend in referrals has decreased over the past 10 years.

We could find no study that looked at the rate of “false positives,” though a 2003 NICS Operations report said the rate had increased by 2 percent when an updated system was implemented, and it was working to reduce that. The report did not specify an actual false-positive rate.

The Pinocchio Test

So where does this leave us? Even accounting for all of the appeals and overturned referrals, it seems as if 1.5 million people over the last 14 years have been denied a firearm. Whether one believes these were all the “wrong people” is more a matter of opinion, but the president is free to make that assertion. Clearly, that many people were denied a firearm — and we have no way of knowing how many ever obtained one in the future.

Still, we are troubled by the lack of detailed data and recent reports that might clarify why so few cases end up being referred for prosecution — especially in light of the 2004 report that said ATF agents did not find many of these people dangerous. We also are troubled by the lack of data on false positives.

But, for the moment, that is not enough to rule this is an inaccurate fact. So, lieu of more evidence, this figure rates a rare Geppetto Checkmark.

Geppetto Checkmark

Glenn Kessler has reported on domestic and foreign policy for more than three decades. He would like your help in keeping an eye on public figures. Send him statements to fact check by emailing him, tweeting at him, or sending him a message on Facebook.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.

To pause and restart automatic updates, click "Live" or "Paused". If paused, you'll be notified of the number of additional comments that have come in.

Comments our editors find particularly useful or relevant are displayed in Top Comments, as are comments by users with these badges: . Replies to those posts appear here, as well as posts by staff writers.